1. Field of the Invention
The present invention relates to an apparatus and method for estimating a chord corresponding to an input musical signal.
2. Description of the Related Art
To date, as a technique for estimating a chord corresponding to an input musical signal, a technique, in which frequency-component data extracted from a musical signal is folded for each one octave (12 tones including C, C#, D, D#, E, F, F#, G, G#, A, A#, B) to generate an octave profile, and the octave profile is compared with a standard chord profile to estimate a chord, has been known (refer to Japanese Unexamined Patent Application Publication No. 2000-298475).
Also, in recent years, a technique, in which a chord is estimated using a Bayesian network having the frequency of a frequency peak after performing short-time Fourier transform on a musical signal and the loudness thereof, a root (root tone), a chroma (chord type: major, minor, etc.), etc., as nodes, has also been known (refer to Randal J. Leistikow et al., “Bayesian Identification of Closely-Spaced Chords from Single-Frame STFT Peaks.”, Proc. of the 7th Int. Conference on Digital Audio Effects (DAFx'04), Oct. 5-8, 2004).